Linear compounds containing phenolic and salicylic units

ABSTRACT

A linear compound and a metal salt or boron-containing metal salt thereof contains one or more carboxyl-containing phenol units or derivatives thereof and one or more on average at least C 18  hydrocarbyl-substituted hydroxyaromatic units or derivatives thereof connected by one or more divalent bridging groups. A concentrate contains the linear compound or metal salt thereof and an organic diluent. A lubricating oil composition contains a minor amount of the linear compound or metal salt thereof and a major amount of a lubricating oil. Additional embodiments of the invention are processes to make the linear compound and the metal salt thereof.

This application is a 371 of PCT/US02/26592 filed Aug. 21, 2002 whichclaims benefit of Ser. No. 60/314,825 filed Aug. 24, 2001.

FIELD OF THE INVENTION

This invention relates to linear compounds in the form of oligomers orpolymers containing substituted phenol units and unsubstituted orsubstituted salicylic acid units. These compounds and metal salts ofthese compounds are useful as additives for lubricants.

BACKGROUND OF THE INVENTION

Lubricating oil compositions for gasoline fueled engines and dieselengines typically contain a variety of additives such as detergents anddispersants, antiwear agents, etc. Lubricating oils for medium- orlow-speed diesel engines are known and will typically contain a range ofadditives which will perform a variety of functions: for example theymay comprise dispersants to minimize deposit formation in various partsof the engine or detergent additives. However contamination of theselubricating oil compositions with unburned residual fuel oil is aproblem recognized in the industry. This leads to severe enginecleanliness problems in service, which is sometimes referred to as“black paint.” The problem is particularly widespread in 4-stroketrunk-piston engines where dirty cam boxes and crankcases areencountered. However, the problem is not confined to 4-stroke engines;2-stroke crosshead engines can also suffer from the problem. These2-stroke engines will usually use two separate lubricating oils, one forthe crankcase and one for the cylinder, but it is in the crankcase wherethe heavy deposits potentially occur. It might be expected that theproblem would be overcome simply by using more of the conventionaldispersant additive in the lubricating oil, but this measure has metwith very limited success.

Acidity in lubricating oil is another long-recognised problem. In theoperation of the internal combustion engine by-products from thecombustion chamber often blow by the piston and admix with thelubricating oil. Additives are generally employed to neutralise theacidic materials and disperse sludge within the lubricating oil.Examples are overbased alkaline earth metal sulfurizedhydrocarbyl-substituted phenates, salicylates, naphthenates andsulfonates. The term “overbased” is generally used to describe thosealkaline earth metal hydrocarbyl-substituted salts in which the ratio ofthe number of equivalents of the alkaline earth metal moiety to thenumber of equivalents of the acid moiety is greater than one. The ratiois usually greater than 1.2 and may be as high as 4.5 or greater. Incontrast, the equivalent ratio of alkaline earth metal moiety to acidmoiety in “normal” or “neutral” alkaline earth metalhydrocarbyl-substituted salts is one, and in “low-based” salts is lessthan one. The metal ratio is referred to herein by the term “MR.” Theoverbased material usually contains greater than 20% in excess of thealkaline earth metal present in the corresponding neutral material. Forthis reason overbased alkaline earth metal hydrocarbyl-substituted saltshave a greater capability for neutralising acidic matter than do thecorresponding neutral alkaline earth metal hydrocarbyl-substitutedsalts, though not necessarily an increased detergency power. The degreeof overbasing is expressed as “Total Base Number” or TBN, which is alsosometimes referred to as Alkalinity Value or AV, and is measured by themethod of ASTM Procedure D-2896.

International publications WO 99/25677 and WO 99/25793 disclosecalixarenes containing within the calixarene ring at least one salicylicacid. The use of these compounds as fuel additives and lubricantadditives is disclosed. Metal salts of these compounds as well as theuse of such metal salts as lubricant additives are disclosed. Thesereferences indicate that in order to provide the calixarene ringstructure it is necessary to use a reaction mixture containing at least50% by weight solvent, preferably at least 80% by weight solvent, morepreferably at least 90% by weight solvent. The references indicate thatat solvent concentrations well below 50% by weight linear molecules areformed.

Copending U.S. patent application Ser. No. 09/802,500 filed Mar. 9,2001, relates to linear phenol-salicylic acid condensation products usedas lubricant and fuel additives.

European Patent Publication EP 0708171 A2 relates to lubricantscontaining metal salts, preferably overbased salts, ofhydrocarbyl-substituted carboxyalkylene-linked phenols, dihydrocarbylesters of alkylene dicarboxylic acids, the alkylene group beingsubstituted with a hydroxy group and an additional carboxylic acidgroup, or alkylene-linked polyaromatic molecules, the aromatic moietieswhereof comprise at least one hydrocarbyl-substituted phenol and atleast one carboxy phenol, where the hydrocarbyl groups are of sufficientlength to provide oil solubility to the salts and the salts exhibit goodasphaltene suspension for marine diesel applications.

One object of this invention is to provide dispersant and detergentcompositions for use in lubricating oil compositions.

Another object is to provide lubricating oil compositions with improveddispersancy performance, particularly with respect to reduction orelimination of “black paint” deposits.

It has now been found that considerably improved performance withrespect to reduction or elimination of ‘black paint’ can be obtainedwith the compositions of this invention wherein the phenolic segmentsare substituted with hydrocarbyl groups containing on average at least18 carbon atoms. It has also been observed that these provide excellentantioxidant properties. Moreover, we have also found that this effect isso marked that the phenolic sections may not have to be purely C₁₈ orgreater substituted hydrocarbyl phenols, they can be mixtures of lowerthan C₁₈ and greater than C18 substituted hydrocarbyl phenols with noloss in anti-black paint performance, and possible economic advantages.

One of the main contributors to the sulfur and phosphorus level in acrankcase engine oil is the zinc dithiophosphate (ZDTP) antiwear agent.When the novel C¹⁸⁻¹⁸⁺ alkylphenol-formaldehyde-salicylic acid resincompounds of this invention are overbased in the presence of boric acidso as to contain boron in the end overbased product, these are both goodantiwear agents and detergents which can partially or fully replace ZDTPantiwear agents and sulfur-containing overbased detergents. The ZDTPantiwear agent level in the crankcase engine oil may be reduced, thuslowering the phosphorus and sulfur content of the crankcase engine oil.The sulfur level will be reduced further by the presence of sulfur freenovel boron containing compound rather than traditional sulfurcontaining overbased detergents such as phenates and sulphonates.

SUMMARY OF THE INVENTION

This invention relates to a linear compound comprising m units offormula (I)

and n units of the formula (II)

joined together, each end of the compound having a terminal unit whichis independently hydrogen or one of the following formulae

wherein at least one of the terminal units is formula (III) or (IV); Yis a divalent bridging group which may be the same or different in eachunit and that joins together units of formulae (I)-(IV); R⁰ is hydrogenor a hydrocarbyl group, R⁵ is hydrogen or a hydrocarbyl, j is 1 or 2;R³is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group;either R¹ is hydroxyl and R² and R⁴ are independently either hydrogen,hydrocarbyl or hetero-substituted hydrocarbyl, or R² and R⁴ are hydroxyland R¹ is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbylprovided that at least one of R¹, R², R³ and R⁴ is hydrocarbylcontaining on average at least 18 carbon atoms; m+n is at least 1;wherein on average the compound contains at least one unit of formula(I) or (III) and at least one unit of formula (II) or (IV); and thecompound has a ratio of total number of units of formulae (I) and (III)to total number of units of formulae (II) and (IV) of about 0.1:1 toabout 2:1. The invention further provides for metal salts of theforegoing compounds including boron-containing metal salts. The linearcompounds and salts are useful as lubricant additives.

In engine oils for passenger cars and trucks there is pressure byoriginal engine manufacturers to reduce the sulphur and phosphoruslevels due to the possibility of sulphur and phosphorus compoundsinterfering with the functioning of exhaust emission treatment devices.The novel C₁₈ or greater alkylphenol-formaldehyde resin compounds whichcontain within the oligomer at least one salicylic acid unit aresulphur-free, so once overbased, will offer an advantage over moretraditional sulphur containing overbased detergents such as phenates andsulphonates.

One of the main contributors to the sulphur and phosphorus level in acrankcase engine oil is the zinc dithiophosphate (ZDTP) antiwear agent.We have found that if the novel C₁₈ or greater alkylphenol-formaldehyderesin compounds which contain within the oligomer at least one salicylicacid unit are overbased in the presence of boric acid, so as to containaround 0.4% B in the end overbased product, these are good antiwearagents. This can allow the ZDTP antiwear agent level in the crankcaseengine oil to be lowered, thus lowering the phosphorus and sulphur levelof the crankcase engine oil. The sulphur level will be lowered stillfurther by the presence of the sulphur-free novel boron-containingcompound just described, rather than traditional sulphur containingoverbased detergents such as phenates and sulphonates.

The inventive linear compounds, at least in one embodiment, are usefulin the inventive lubricating oil compositions as surfactants and/orantioxidants. The metal salts, including the boron-containing metalsalts, of the inventive linear compounds are useful in the inventivelubricating oil compositions, at least in one embodiment, as detergentsor as both detergents and antiwear agents and in one embodiment, inreducing black paint in low- or medium-speed diesel engines.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The term “hydrocarbyl” denotes a group having a carbon atom directlyattached to the remainder of the molecule and having a hydrocarbon orpredominantly hydrocarbon character within the context of thisinvention. Such groups include the following:

(1) Purely hydrocarbon groups; that is, aliphatic, (e.g., alkyl oralkenyl), alicyclic (e.g., cycloalkyl or cycloalkenyl), aromatic,aliphatic- and alicyclic-substituted aromatic, aromatic-substitutedaliphatic and alicyclic groups, and the like, as well as cyclic groupswherein the ring is completed through another portion of the molecule(that is, any two indicated substituents may together form an alicyclicgroup). Such groups are known to those skilled in the art. Examplesinclude methyl, ethyl, octyl, decyl, octadecyl, cyclohexyl, phenyl, etc.

(2) Substituted hydrocarbon groups; that is, groups containingnon-hydrocarbon substituents which do not alter the predominantlyhydrocarbon character of the group. Those skilled in the art will beaware of suitable substituents. Examples include hydroxy, nitro, cyano,alkoxy, acyl, etc.

(3) Hetero groups; that is, groups which, while predominantlyhydrocarbon in character, contain atoms other than carbon in a chain orring otherwise composed of carbon atoms. Suitable hetero atoms will beapparent to those skilled in the art and include, for example, nitrogen,oxygen and sulfur.

In general, no more than about three substituents or hetero atoms, andpreferably no more than one, will be present for each 10 carbon atoms inthe hydrocarbyl group.

The terms “hydrocarbon” and “hydrocarbon-based” have the same meaningand can be used interchangeably with the term hydrocarbyl when referringto molecular groups having a carbon atom attached directly to theremainder of a molecule.

The term “lower” as used herein in conjunction with terms such ashydrocarbyl, alkyl, alkenyl, alkoxy, and the like, is intended todescribe such groups that contain a total of up to 7 carbon atoms.

The term “oil-soluble” refers to a material that is soluble in mineraloil to the extent of at least about one gram per liter at 25° C.

The term “TBN” refers to total base number. This is the amount of acid(perchloric or hydrochloric) needed to neutralize all or part of amaterial's basicity, expressed as milligrams of KOH per gram of sample,measured by ASTM Procedure D-2896.

The Linear Compounds

The inventive linear compounds are in the form of linear oligomers orpolymers containing units represented by the formulae (I), (II), (II)and (IV) depicted hereinabove. These compounds are comprised of unitsrepresented by formulae (I) and (II) connected to each other. At eachend of the compound is a terminal unit which is independently hydrogenor one of the formulae represented by (III) or (IV) wherein at least oneof the terminal units is formula (III) or (IV). The units represented byformulae (I) and (II) may be distributed in random or block patterns.Preferably, the compound contains on average at least one unitrepresented by formulae (I) or (III) and at least one unit representedby formulae (II) or (IV). For example, the linear compounds may includeone or more block of units corresponding to -(II)(II)-, -(II)(II)(II)-,-(II)(II)(II)(II)-, etc.

Examples of the inventive compounds include the following

-   -   (III)-(IV)    -   (III)-(II)-(IV)    -   (III)-(II)-(II)-(II)-(I)-(II)-(III)    -   (III)-(II)-(I)-(I)-(II)-(II)-(II)-(IV)    -   (IV)-(I)-(I)-(II)-(II)-(II)-(I)-(III)    -   (III)-(II)-(II)-(I)-(II)-(II)-(III)    -   (IV)-(I)-(II)-(II)-(II)-(II)-(II)-(IV)    -   (III)(II)(II)(II)(II)(II)(II)(I)(II)(II)(II)(IV)    -   (IV)((II))₁₀(I)((II))₅(I)(I)((II))₈(I)(IV)    -   (III)((I))₅(II)((I))₁₀(II)(II)(II)(IV)    -   (IV)((II)₂₀(I)((II))₁₀(I)(IV)    -   (IV)((II))₄₀(I)(I)(II)₅(IV)        The total number of units represented by formula (I) in the        inventive linear compound is m, and the total number of units        represented by formula (II) is n. In one embodiment m is at        least 1 and n is at least 2. The total of m+n is at least 2.        preferably at least 3, and in one embodiment at least about 4,        and in one embodiment at least about 5, and in one embodiment at        least about 6, and in one embodiment at least about 7, and in        one embodiment at least about 8. The total of m+n may range from        2, often from about 3 to about 50, and in one embodiment about 4        to about 50, and in one embodiment about 5 to about 50, and in        one embodiment about 6 to about 50, and in one embodiment about        7 to about 50, and in one embodiment about 8 to about 50, and in        one embodiment 3 to about 40, and in one embodiment 3 to about        30, and in one embodiment 3 to about 20. The ratio of m to n        ranges from about 0.1:1 to about 2:1, and in one embodiment        about 0.1:1 to about 1:1, and in one embodiment about 0.1:1 to        about 0.5:1, and in one embodiment 0.1:1 to about 0.3:1, and in        one embodiment about 0.1 4-0.15:1.

In formulae (I) and (II), each Y is a divalent bridging group that joinstogether the units of formulae (I)-(IV) and that may independently berepresented by the formula (CHR⁶)_(d) in which R⁶ is either hydrogen orhydrocarbyl and d is an integer which is at least 1. In one embodiment,R⁶ contains 1 to about 6 carbon atoms, and in one embodiment 1 or 2carbon atoms, and in one embodiment it is methyl. In one embodiment, dis from 1 to about 4. Y may optionally be sulfur rather than (CHR⁶)_(d)in up to 50% of the units, such that the amount of sulfur incorporatedin the molecule is up to 50 mole %. In one embodiment, the amount ofsulfur is between 8 and 20 mole %, and in one embodiment the compound issulfur-free.

In formulae (I) and (III), R⁰ is hydrogen or a hydrocarbyl (e.g., alkyl)group of 1 to about 6 carbon atoms, and in one embodiment 1 or 2 carbonatoms. R⁵ is hydrogen or a hydrocarbyl group of 1 to about 10 carbonatoms, and in one embodiment 1 to about 6 carbon atoms, and in oneembodiment 1 to about 3 carbon atoms, and in one embodiment 1 to about 8carbon atoms, and in one embodiment 1 to about 2 carbon atoms.

In formulae (II) and (IV), R³ is hydrogen or a hydrocarbyl of 1 to about200 carbon atoms, and in one embodiment 1 to about 100 carbon atoms, andin one embodiment 1 to about 60 carbon atoms, and in one embodiment 1 toabout 30 carbon atoms, and in one embodiment 1 to about 18 carbon atoms,in one embodiment about 12 carbon atoms, and in one embodiment onaverage at least 18 carbon atoms. R³ may be dodecyl or derived frompropylene tetramer. R³ may be hetero-substituted. The hetero atoms orgroups may be —O— or —NH—. In one embodiment, R³ is an alkoxyalkylgroup; either R¹ is hydroxyl and R² and R⁴ are independently eitherhydrogen, hydrocarbyl or hetero-substituted hydrocarbyl, or R² and R⁴are hydroxyl, and R¹ is either hydrogen, hydrocarbyl orhetero-substituted hydrocarbyl. The hydrocarbyl and hetero-substitutedhydrocarbyl groups independently contain 1 to about 200 carbon atoms,and in one embodiment 1 to about 100 carbon atoms, and in one embodiment1 to about 60 carbon atoms, and in one embodiment 1 to about 30 carbonatoms, and in one embodiment 1 to about 18 carbon atoms, and in oneembodiment 1 to about 12 carbon atoms, and in one embodiment 1 to about6 carbon atoms. The hetero substituents may be —O— or —NH—, providedthat at least one of R¹, R², R³ and R⁴ is hydrocarbyl containing onaverage at least 18 carbon atoms and preferably at least 30 carbonatoms.

In one embodiment, Y is CH₂; R¹ is hydroxyl; R² and R⁴ are hydrogen; R³is a hydrocarbyl group of about 18 to about 200 carbon atoms, often toabout 60 carbon atoms, and in one embodiment about 18 to about 45 carbonatoms, and in one embodiment about 18 to about 30 carbon atoms, and inone embodiment from about 30, often from about 40 to about 100 carbonatoms, and in one embodiment about 30 to about 60 carbon atoms; R⁰ ishydrogen; R⁵ is hydrogen; j is 1; and m+n has a value of at least 1, andin one embodiment at least 2, and in one embodiment at least about 3;and m is 0, 1 or 2, and in one embodiment m is 1.

In one embodiment, either or both of the terminal groups represented bythe formulae (III) and (IV) has a —CH₂OH group attached to the aromaticring in an ortho position relative to the hydroxyl group.

In an embodiment of the present invention the linear compound containsone or more units of formulae (II) and (IV) wherein a portion of saidunits have a R³ hydrocarbyl group containing about 8 to about 20 carbonatoms and a remaining portion of said units having a R³ hydrocarbylgroup containing about 21 to about 45 carbon atoms where the R³hydrocarbyl groups from the said portions on average contain at least 18carbon atoms. This linear compound having R³ groups containing onaverage at least 18 carbon atoms can be prepared in several ways. Thecompound can be prepared from a mixture of starting units of formulae(II) and (IV) having R³ groups with different numbers of carbon atomssuch as C₁₂ and C₄₀R³ groups. The compound can also be prepared bymixing two or more compounds where each of these compounds is preparedfrom units of formulae (II) and (IV) having a R³ group with a givennumber of carbon atoms; e.g., the compound is prepared by mixingcompound 1 and compound 2 where compound 1 contains C₁₂R³ groups andcompound 2 contains C₄₀R³ groups.

The process for making the inventive linear compounds comprises reactingtogether optionally in an organic solvent, in the presence of a basiccatalyst, compounds of the formulas (Ia) and (IIa)

with an aldehyde of the formula O═CHR⁶, and optionally sulfur; where R⁰to R⁶ and j are as defined previously.

The formaldehyde may be paraformaldehyde, an aqueous solution ofaldehyde (formalin), or a solution of an aldehyde in methanol.

The basic catalyst may be an alkali or alkaline earth metal hydroxidesuch as sodium hydroxide, potassium hydroxide, and the like; ammonia; ora hindered amine. The hindered amines that are useful include tetraalkyl ammonium hydroxides such as tetra methyl ammonium hydroxide,tetrabutyl ammonium hydroxide, and the like, as well as the trialkylmonoamines such as triethyl amine, and the like. The molar ratio of thebasic catalyst to the number of moles of compound represented by formula(IIa) may range from about 0.005:1 to about 0.5:1, and in one embodimentabout 0.02:1 to about 0.3:1, and in one embodiment about 0.02-0.04:1.

Alternatively, the basic catalyst may be a basic ion exchange resin suchas the AMBERLITE® resins provided by Rohm & Haas or the DOWEX® resinsprovided by Dow. These are macroreticular resins which are stronglybasic in nature and have moderate porosities. Specific resins that maybe used include Amberlite IRA 410 and Dowex 550 OH. These resins may beused at a concentration of about 0.1 to about 30% by weight based on theoverall weight of the reaction mixture, and in one embodiment about 0.1to about 10% by weight.

As noted hereinabove, the reaction of this invention may be conducted inthe presence of an organic solvent such as toluene, a mineral oil, or amixture thereof. Frequently, the concentration of organic solvent (ifused) in the reaction mixture is up to about 48% by weight of thereaction mixture, and in one embodiment from about 5% to about 48% byweight, and in one embodiment about 15% to about 48% by weight, and inone embodiment about 30% to about 48% by weight of the reaction mixture.In one embodiment, the solvent comprises about 32% to about 46% byweight of the reaction mixture, and in one embodiment about 35% to about45% by weight.

The reactants corresponding to (Ia) and (IIa) may be combined with thealdehyde simultaneously or stepwise.

In one preferred embodiment, the compounds corresponding to formula(IIa) are permitted to oligomerize, at least partially, before addingthe compounds corresponding to formula (Ia) to the reaction mixture.Thus, in this embodiment of the inventive process, the compoundcorresponding to formula (IIa) is mixed with the solvent (if used) andreacted with the aldehyde in the presence of the basic catalyst prior tothe addition of the compound corresponding to formula (Ia). As a result,the inventive linear compounds of this embodiment will contain at leastone block of one or more units corresponding to formula (IIa) linked toeach other. For example, the inventive linear compounds may have one ormore blocks of units corresponding to -(IIa)-(IIa)(IIa)-,-(IIa)(IIa)(IIa)-, -(IIa)(IIa)(IIa)(IIa)-, etc.

Metal Salts of the Linear Compounds

In one embodiment of the invention, low based, neutral or overbasedsalts of the inventive linear compounds are provided. The process formaking the low-based or neutral salts comprises the steps of: (I)forming a mixture of components (A) and (C); and (II) adding a metalbase (B) to the mixture of components (A) and (C), the addition of themetal base (B) to the mixture of (A) and (C) being in a single additionor in a plurality of additions, steps (I) and (II) being performedconcurrently or sequentially.

Component (A) may be either (i) the inventive linear compound having atleast one substituent hydroxyl group available for reaction with a metalbase, or (ii) a low-based or neutral metal salt of the inventive linearcompound having at least one substituent hydroxyl group available forreaction with the metal base.

Component (B) is a metal base. The metal moiety may be an alkali oralkaline earth metal, and in one embodiment an alkaline earth metal. Themetal may be calcium, magnesium or barium, and in one embodiment it iscalcium. The base moiety may be an oxide or a hydroxide. A calcium basemay be added, for example, in the form of quick lime (CaO) or in theform of slaked lime (Ca(OH)₂) or mixtures of the two in any proportion.Component (B) may be added in whole to the initial reactants or in partto the initial reactants and the remainder in one or more furtheradditions at intermediate points during the reaction.

Component (C) is solvent comprising either component (C-1) or (C-2).Component (C-1) is either (i) a polyhydric alcohol having about 2 toabout 4 carbon atoms, (ii) a di-(C₃ or C₄)glycol, (iii) atri-(C₂-C₄)glycol or (iv) a mono- or poly-alkylene glycol alkyl ether ofthe formula:R¹(OR²)_(f)OR³  (V)wherein in the formula (V), R¹ is an alkyl group of 1 to about 6 carbonatoms, R² is an alkylene group of 1 to about 6 carbon atoms; R³ ishydrogen or an alkyl group of 1 to about 8 carbon atoms, and f is aninteger from 1 to about 6. Examples include the monomethyl or dimethylethers of ethylene glycol, diethylene glycol, triethylene glycol ortetraethylene glycol. A useful compound is methyl diglycol. Mixtures ofglycol ethers and glycols may be used. The polyhydric alcohol may beeither a dihydric alcohol, for example ethylene glycol or propyleneglycol, or a trihydric alcohol, for example glycerol. The di-(C₃ orC₄)glycol may be dipropylene glycol, and the tri-(C₂ to C₄)glycol may betriethylene glycol.

In one embodiment, component (C-1) further comprises: (a) a hydrocarbonsolvent; or (b) either (i) water, (ii) a monohydric alcohol of 1 toabout 20 carbon atoms, (iii) a ketone having up to 20 carbon atoms, (iv)a carboxylic ester having up to 10 carbon atoms, (v) an aliphatic,alicyclic or aromatic ether having up to 20 carbon atoms, or a mixtureof two or more of (i) to (v). Examples include methanol, 2-ethylhexanol, cyclohexanol, cyclohexanone, benzyl alcohol, ethyl acetate andacetophenone.

Component (C-2) is a monohydric alcohol of 1 to about 4 carbon atoms incombination with a hydrocarbon solvent.

The hydrocarbon solvent may be aliphatic or aromatic. Examples ofsuitable hydrocarbon solvents include toluene, xylene, naphtha andaliphatic paraffins, for example hexane, and cycloaliphatic paraffins.

In one embodiment, it is useful to incorporate an oil of lubricatingviscosity as a supplemental solvent. The oil may be an animal, vegetableor mineral oil. The oil may be a petroleum derived lubricating oil, suchas a naphthenic base, paraffin base or mixed base oil. Solvent neutraloils may be used. The oil may be a synthetic oil. Suitable syntheticoils include synthetic ester oils, which oils include diesters such asdi-octyl adipate, di-octyl sebacate and tri-decyladipate, or polymerichydrocarbon oils, for example liquid polyisobutenes and poly-alphaolefins.

Useful solvents (C) include ethylene glycol, a mixture of ethyleneglycol and 2-ethyl hexanol, and a mixture of methanol and toluene.

In one embodiment, the invention includes a process for the productionof overbased metal salts of the inventive linear compounds whichcomprises the foregoing process for making a low based or neutral metalsalt of the inventive linear compound but with the addition of thefollowing step: (III) adding (D) carbon dioxide to the mixture ofcomponents (A), (B) and (C) subsequent to each addition of component(B). The carbon dioxide may be added in the form of a gas or a solid,preferably in the form of a gas. In gaseous form it may be blown throughthe reaction mixture.

The weight ratio of component (A) to component (C) may be from about 10to about 65 parts by weight of (A) per 100 parts by weight of (C), andin one embodiment about 20 to about 60 parts by weight of (A) per 100parts by weight of (C). The ratio of mole equivalents of component (B)to mole equivalents of component (A) may be from about 0.05 to about 20mole equivalents of (B) per mole equivalent of (A), and in oneembodiment about 0.08 to about 18 mole equivalents of (B) per moleequivalent of (A). The ratio of the number of moles of metal incomponent (B) to the number of moles of carbon dioxide in (D) may befrom about 0.3 to about 1.6 moles of metal in (B) per mole of carbondioxide in (D), and in one embodiment about 0.55 to about 1.3 moles ofmetal in (B) per mole of carbon dioxide in (D).

In one embodiment, the reaction mixture may include component (E).Component (E) is either (i) a carboxylic acid containing from about 6 toabout 100 carbon atoms or an anhydride thereof, (ii) a di- orpolycarboxylic acid containing from about 36 to about 100 carbon atomsor an anhydride thereof, (iii) a hydrocarbyl-substituted sulphonic acidor an anhydride thereof, (iv) a hydrocarbyl-substituted salicylic acidor an anhydride thereof, (v) a hydrocarbyl-substituted naphthenic acidor an anhydride thereof, (vi) a hydrocarbyl-substituted phenol or (vii)a mixture of any two of (i) to (vi). Component (E) may be added duringstep (I), (II) or (III), or prior to or subsequent to any of theforegoing steps. In one embodiment, component (E) is added during step(I). When component (E) is used, it may be used in an amount of up toabout 40% by weight based on the combined weight of components (A), (B),(C), (D) and (E), and one embodiment from about 2 to about 38% byweight, and in one embodiment from about 12 to about 27% by weight.

Component (i) of component (E) may be an acid having the formula:

wherein in formula (VI), R¹ is an alkyl or alkenyl group of about 10 toabout 24 carbon atoms, and R² is either hydrogen, an alkyl group of 1 toabout 4 carbon atoms or a —CH₂COOH group. R¹ may be an unbranched alkylor alkenyl group. Examples of the saturated acids that may be usedinclude capric, lauric, myristic, palmitic, stearic, isostearic,arachidic, behenic and lignoceric acids. Examples of the unsaturatedacids that may be used include lauroleic, myristoleic, palmitoleic,oleic, gadoleic, erucic, ricinoleic, linoleic and linolenic acids.Mixtures of any of the foregoing acids may also be employed, forexample, ripe top fatty acids. Suitable mixtures of acids are thosecommercial grades containing a range of acids, including both saturatedand unsaturated acids. Such mixtures may be obtained synthetically ormay be derived from natural products, for example, tall, cotton, groundnut, coconut, linseed, palm kernel, olive, palm, castor, soybean,sunflower, herring and sardine oils and tallow. In one embodiment,component (i) of component (E) is an acid anhydride, acid chloride orester derivative of any of the foregoing acids.

Component (ii) of component (E) may be a polyisobutylene substitutedsuccinic acid or a polyisobutylene substituted succinic anhydride. Themolecular weight of such acid or anhydride may be in the range of about300 to about 3000, and in one embodiment about 700 to about 1300.

As regards to components (iii), (iv), (v) and (vi) of component (E), thehydrocarbyl substituent may contain up to about 125 aliphatic carbonatoms, and in one embodiment about 6 to about 20 carbon atoms. Examplesof suitable substituents include alkyl groups, for example hexyl,cyclohexyl, octyl, isooctyl, decyl, tridecyl, hexadecyl, eicosyl andtricosyl. Hydrocarbyl groups derived from the polymerization of bothterminal and internal olefins, for example ethene, propene, 1-butene,isobutene, 1-hexene, 1-octene, 2-butene, 2-pentene, 3-pentene and4-octene may be used. In one embodiment, the hydrocarbyl substituent isderived from polypropylene, poly-1-butene or polyisobutylene.

The reaction mixture may also include as component (F) a catalyst (orpromoter) for the reaction. The catalyst may be an organic compound oran inorganic compound. The catalyst (F) is added during step (I), (II)or (III), or prior to or subsequent to any of the foregoing steps. Inone embodiment, the catalyst (F) is added during step (I). Whencomponent (F) is used, the amount of component (F), added to the mixtureof (A), (B), (C), (D) and optionally (E) ranges from about 0.1% to about3% by weight based on the combined weight of the mixture, and in oneembodiment about 2% by weight. Suitable organic compounds include (i)organic halides (e.g., chlorides, bromides, iodides) or (ii) organicalkanoates, which may be represented by the formula:R—X  (VII)wherein in formula (VII), R is either an alkyl, aryl or alkaryl groupwhich may have about 3 to about 20 carbon atoms, about 6 to about 20carbon atoms, or about 7 to about 20 carbon atoms, respectively, or ahalo-derivative thereof. X is either halogen, suitably chlorine, bromineor iodine, preferably chlorine, or the group OCOR¹ wherein R¹ is analkyl group of 1 to about 4 carbon atoms. Alternatively, the organichalide may be an HX salt of an organic base, for example guanidinehydrochloride. An example of an organic halide represented by formula(VII) is octyl chloride. Mixtures of (i) and (ii) of component (F) maybe employed. Suitable inorganic compound catalysts include inorganichalides, particularly inorganic chlorides, and inorganic alkanoates.Examples of suitable inorganic compound catalysts include calciumacetate, calcium chloride, ammonium chloride, ammonium acetate, aluminumchloride and zinc chloride. Provided that the catalyst is present duringthe carbonation step (i.e., step (III)), it may be added at any point inthe process, though it is usually convenient to add the catalystinitially during step (I).

In order to produce an overbased salt from component (A)(i) or (A)(ii)it is necessary to react component (A) with components (B), (C) and (D),using the appropriate proportions of components (A) and (B) to achieveoverbasing. Suitably component (B) may be added in one or moreadditions.

In order to produce a high TBN overbased metal salt of the inventivelinear compound there may be employed an overbased metal salt of theinventive linear compound derived from one of the inventive linearcompounds having a substituent group or groups available for reaction,and it is preferred to employ component (E), particularly either (E)(i)or (ii), and more particularly stearic acid, while at the same timeadjusting the relative amounts of components (A) and (B) to a valuesufficient to produce the desired high TBN metal salt.

The temperature at which the process is operated may be a temperature inthe range from about 15 to about 200° C., and in one embodiment fromabout 50 to about 175° C. The selection of the optimum temperaturewithin the aforesaid range is dependent in part on the nature of thesolvent employed.

Generally, the process is operated in the presence of a lubricating oil.At the conclusion of the process it is preferred to recover the salt asa solution in lubricating oil by separating off volatile fractions, forexample, by distillation at subatmospheric pressure. Finally, it ispreferred to filter the solution. Alternatively, the solution may becentrifuged.

Salts produced by the above process may have TBNs of 60 mg KOH/g orbelow, (i.e., low based or neutral metal salt of the inventive linearcompounds). In one embodiment, these have TBN ranging from about 10 to60, often to about 40 and in one embodiment, to about 30. In oneembodiment, the salts are overbased, in which case they generally haveTBNs of greater than 60 mg KOH/g, often at least about 100 mg KOH/g, inone embodiment at least about 200 mg KOH/g, and in one embodiment fromabout 200 up to about 500 mg KOH/g, and in one embodiment from about 300up to about 500 mg KOH/g, and in one embodiment from about 350 up toabout 500 mg KOH/g, and in one embodiment from about 400 up to about 500mg KOH/g.

In an embodiment of the present invention overbased metal salts of thelinear compound, having a TBN ranging from about 60 to about 500 mgKOH/g or from about 100 to about 500 mg KOH/g, can contain boron. Theboron-containing overbased metal salts can be prepared by adding aborating agent, such as boric acid or the alcohol borate tributylborate, any time during or after the preparation of the overbased metalsalts of the linear compound. In one instance the borating agent isadded at the very beginning of the overbasing process. In anotherinstance the borating agent is added to the overbased metal salt of thelinear compound, and the mixture is then heated to temperatures of about100 to about 200° C. sometimes under reduced pressure and/or in presenceof a solvent such as xylenes or toluene to facilitate removal ofvolatile reaction products such as water or alcohols.

The salts including boron-containing salts may be supplied in the formof a concentrate. These concentrates are comprised of the foregoing saltand a substantially inert, normally liquid organic diluent such asmineral oil, synthetic oil (e.g., ester of dicarboxylic acid), naphtha,alkylated (e.g., C₁₀-C₁₃ alkyl) benzene, toluene or xylene to form anadditive concentrate. These concentrates usually contain from about 1%to about 99% by weight, and in one embodiment about 10% to about 90% byweight of the diluent.

Lubricating Oil Compositions

The inventive lubricating oil compositions are based on diverse oils oflubricating viscosity, including natural and synthetic lubricating oilsand mixtures thereof. The lubricating oil compositions may belubricating oils useful in industrial applications and in automotiveengines, transmissions and axles. These lubricating oil compositions areeffective in a variety of applications including crankcase lubricatingoils for spark-ignited and compression-ignited internal combustionengines, including automobile and truck engines, two-cycle engines,aviation piston engines, marine and low-load diesel engines, and thelike.

In one embodiment, the inventive lubricating oil composition is suitablefor use in either low- or medium-speed engines, especially marine dieselengines. Typically such engines are 4-stroke trunk piston engines havingan engine speed of 300-2,000 rpm, and in one embodiment 400-800 rpm, anda brake horse-power (BHP) per cylinder of 10-3,000, and in oneembodiment 150-1,900. The engine can also be a 2-stroke cross-headengine having a speed of 50-350 rpm, and in one embodiment 100-250 rpmand a BHP per cylinder of 500-7,500.

The lubricating oil compositions employ an oil of lubricating viscositythat is generally present in a major amount (i.e. an amount greater thanabout 50% by weight). In one embodiment, the oil of lubricatingviscosity is present in an amount greater than about 60% by weight, orgreater than about 70% by weight, or greater than about 80% by weight.

In one embodiment, the oil of lubricating viscosity is selected toprovide a lubricating composition of at least an SAE gear oil viscositynumber of about 60 or about 65. The lubricating composition may alsohave a so-called multigrade rating such as SAE 60W-80, 65W-80, 65W-90,75W-80, 75W-90, 80W-90, 80W-140 or 85W-140. Multigrade lubricants mayinclude a minor viscosity improving amount of a viscosity improver whichis formulated with the oil of lubricating viscosity to provide the abovelubricant grades. Useful viscosity improvers include polyolefins,styrene-diene polymers and polymethacrylates.

In one embodiment, the oil of lubricating viscosity is selected toprovide lubricating compositions with crankcase applications such as forgasoline and diesel engines. Typically, the lubricating compositions areselected to provide an SAE crankcase viscosity number of 10W, 20W or 30Wgrade lubricants. The lubricating compositions may also have a so-calledmulti-grade rating such as SAE 10W-30, 10W-40, 10W-50, etc. As describedabove, the multi-grade lubricants include a viscosity improver which isformulated with the oil of lubricating viscosity to provide the abovelubricant grades.

Oils of lubricating viscosity generally include natural oils, syntheticoils, and mixtures thereof. Natural oils include animal and vegetableoils such as lard oil and soybean oil, and mineral oils derived fromvarious sources such as petroleum crudes, coal and shale. Synthetic oilsinclude olefin homopolymers and copolymers such as poly(alpha-olefins)and ethylene-propylene copolymers, carboxylic acid esters such asbisesters of dicarboxylic acids, and polyalkylene glycols to includeether and ester derivatives thereof. Specific examples of theabove-described oils of lubricating viscosity are given in Chamberlin,III., U.S. Pat. No. 4,326,972, European Patent Publication 107,282, andA. Sequeria, Jr., Lubricant Base Oil and Wax Processing, Chapter 6,Marcel Decker, Inc., New York (1994), each of which is herebyincorporated by reference for relevant disclosures contained therein. Abasic, brief description of lubricant base oils appears in an article byD. V. Brock, “Lubrication Engineering”, Volume 43, pages 184-5, March,1987, which article is expressly incorporated by reference for relevantdisclosures contained therein.

The lubricating oil compositions of the present invention may have a TBNin the range from about 0.1 to about 100 mg KOH/g. When the compositionis to be used in a 4-stroke trunk piston engine the TBN may be in therange from about 5 to about 70, and in one embodiment about 8 to about50 mg KOH/g. When it is to be used in a 2-stroke cross-head engine andparticularly for the crankcase, the TBN of the composition may be in therange from about 0.1 to about 15, and in one embodiment in the rangefrom about 1 to about 10 mg KOH/g.

The inventive lubricating oil composition may be contaminated with afuel oil which has a residual oil content. These fuel oils are suitablefor use as diesel fuel oils. Fuel oils can in general be divided intotwo main categories, namely, distillates and heavy fuels. Distillatesconsist of one or more distilled fractions. Heavy fuels are fuels thatcomprise at least a proportion of a residual oil; that is, an oil thatremains after the distilled fractions have been removed from anunrefined oil. The composition of the residual oil will vary with thecomposition of the starting oil which is usually a crude oil and willalso vary depending upon the distillation conditions. However, by itsnature residual oil is of high molecular weight and high boiling point.Heavy fuels can also comprise, in addition to residual oil, distillates.However, heavy fuels generally comprise at least about 90% by weight,and in one embodiment at least about 95% by weight, and in oneembodiment at least about 99% by weight residual oil. In one embodiment,the present invention relates to lubricating oil compositions that arecontaminated with a heavy fuel. The amount of heavy fuel in thelubricating oil composition will vary. The lubricating oil compositionmay contain between about 0.1 to about 25% by weight, and in oneembodiment about 0.1 to about 10% by weight, and in one embodiment about0.3 to about 5% by weight, and in one embodiment, about 0.5 to about 3%by weight heavy fuel oil, which as defined above is a fuel oil which hasa residual oil content. The use of these contaminated lubricating oilcompositions in low- or medium-speed diesel engines such as 4-strokepiston engines and 2-stroke cross-head engines can lead to an enginecleanliness problem known as “black paint.” By including the inventivelinear compounds or metal salts thereof in these contaminatedlubricating oil compositions the problem of black paint may be reducedor eliminated. Overbased metal salts of these compounds also function ashigh TBN detergents, thereby providing two functions in one product.

In addition to the lubricating oil and the inventive linear compound ormetal salt or boron-containing metal salt thereof, the inventivelubricating oil compositions may contain other additives known in theart. These include dispersants. Although any type of dispersant may beemployed in the composition, a suitable dispersant is one derived from ahydrocarbyl-substituted succinic acid or anhydride by reaction with anamine, i.e. a hydrocarbyl-substituted succinimide such as apolyisobutylene-substituted succinimide. These succinimides are wellknown in the art. Succinimide production is described in, for example,the following U.S. Pat. Nos.: 2,992,708; 3,018,291; 3,024,237;3,100,673; 3,219,666; 3,172,892; 3,272,746; 4,234,435; 4,904,410 and6,165,235. Succinimide dispersants that are mono- or bis-succinimidesmay be employed.

In addition to the foregoing, the inventive lubricating oil compositionmay contain one or more additives conventionally employed in lubricatingoil compositions. Examples of such additives include additionaldetergents, foam inhibitors, extreme pressure/antiwear agents, rustinhibitors, antioxidants, and the like. The additional detergents thatcan be employed include hydrocarbyl-substituted alkaline earth metalphenates, salicylates, naphthenates, sulphonates or carboxylates, whichmay be neutral or overbased materials. The concentration of each ofthese when used may range from about 0.001% to about 20% by weight.

The lubricating oil composition of the present invention can be preparedby mixing a concentrate comprising an organic diluent and a linearcompound or metal salt thereof of this invention, optionally a suitablediluent such as a hydrocarbon solvent or mineral oil, and optionallyother useful additives described hereinabove with the oil of lubricatingviscosity until the mixture is homogeneous.

In one embodiment, the inventive lubricating oil composition contains adetergency-improving and black paint-reducing amount of the inventivelinear compound or metal salt thereof of about 0.01 to about 10% byweight of the inventive linear compound or metal salt thereof based onthe weight of the lubricating oil composition, in one embodiment about0.01 to about 7% by weight, in one embodiment about 0.01 to about 5% byweight, in one embodiment about 0.05 to about 4% by weight, and in oneembodiment about 0.1 to 3% by weight.

As indicated above, the inventive linear compounds or metal saltsthereof may be used for reducing black paint in low- or medium-speeddiesel engines. The lubricating compositions used for these applicationsmay comprise up to about 5% to about 10% by weight, and in oneembodiment from about 0.1% to about 3% by weight of ahydrocarbyl-substituted succinimide dispersant; from about 0.05 to about5% by weight, and in one embodiment from about 0.1% to about 3% of ainventive linear compound or metal salt thereof; and a low-ormedium-speed diesel engine lubricating oil.

The following examples illustrate compositions of this invention. Alltemperatures are in degrees Celsius (° C.), parts and percentages are byweight. Filtrations are conducted with a diatomaceous earth filter aid.SN150 oil is a 150 neutral oil obtained from Exxon.

EXAMPLE 1

A 2 L flange flask is charged with 346 g dodecylphenol (propylenetetramer derived, 1.32 moles, 1 equivalent (eq)); 95.6 g salicylic acid(0.69 mole, 0.52 eq); 226.9 g of 36.7% by weight formaldehyde in water(formalin) (1.70 moles, 1.356 eq); 45 g 25% aqueous ammonia (0.65 mole,0.5 eq), and 500 g toluene (solvent). A reaction apparatus is set upusing the flask, a flange lid and clip, overhead stirrer with paddle andpolytetrafluoroethylene (PTFE) stirrer gland, Dean Stark trap and doublesurface condenser, an electric mantle/thermocouple/Eurotherm temperaturecontroller system, the glassware from just above the mantle to justbelow the condenser being covered with glass wool. The reactor contentsare heated with stirring to 85° C. and are held for 1.5 hours. Thetemperature is increased to 105° C., and maintained for 3 hours whilecollecting 229 g water via the Dean & Stark trap. The temperature isincreased to 120° C. and is maintained for 1.5 hours with refluxingtoluene. The toluene is removed on a rotary evaporator at 100° C. and 75mm Hg then mixed with sufficient mineral oil (SN150) to provide a 50%solution. The solution is the product. Yield=1011 g, 100%. Mass specindicates that the product consists of a mixture of linear compoundscontaining units derived from both dodecyl phenol and salicylic acid, amajority of which is 2 dodecylphenol molecules and 1 salicylic acidmolecule methylene bridged together.

EXAMPLES 2-4 as indicated below were prepared following the procedure ofExample 1:

Example 2—1 equiv of C₁₈ phenol coupled with 1.3 equiv of salicylicacid,

Example 3—1 equiv of C₁₈ phenol coupled with 0.5 equiv of salicylicacid, and

Example 4—1 equiv of polyisobutyl (550 mol. wt.) phenol coupled with 1equiv of salicylic acid.

EXAMPLE 5

The apparatus used in Example 1 is used. The flask is charged with 475 gpolyisobutenyl ( M _(n) 550, derived from GLISSOPAL® 550 (BASF))substituted phenol (0.739 mole, 1 eq) and 330 g mineral oil (SN150) andheated to 30° C. Via a pressure equalizing dropping funnel, 3.4 g of 50%aqueous KOH (0.030 mole, 0.04 eq) are added all at once. The materialsare heated to 75° C. followed by addition over 0.5 hour via a pressureequalizing dropping funnel, 81.6 g 37% aqueous formaldehyde (formalin)(1.01 moles, 1.367 eq) followed by heating at 75° C. for 2 hours untilfree formaldehyde measures less than 2% (by titration). To the reactionare charged 51.6 g salicylic acid (0.374 mole, 0.51 eq) and the reactionis heated to 140° C. as quickly as possible (0.3 hour) while controllingreflux, draining water of reaction via a Dean Stark trap. The reactionis held at 140° C. for 1.5 hours while collecting 58 ml water. Thematerials are vacuum stripped at 140° C./100 mm Hg over 0.5 hour. Theclear and golden residue is the product. Yield=857 g, % K=0.093%. Massspec, GPC and H¹ and C¹³ NMR indicate that the product consists of 2methylene bridged polyisobutenyl phenol molecules methylene bridged toone salicylic acid.

Example 6 was a repeat of Example 5 on a larger scale.

EXAMPLE 7

A 2-liter flask is charged with 250 g (0.58 mole, 1 eq) of thedodecylphenol-salicylic acid resin of Example 1,30 g dodecylphenol(propylene tetramer derived) (0.115 mole, 0.12 eq), 125 g tall oil fattyacid (0.442 mole, 0.76 eq), 15 g (0.24 mole, 0.4 eq) ethylene glycol, 90g (1.22 mole, 2.1 eq) Ca(OH)₂, 40 g mineral oil (SN150) and 260 g2-ethylhexanol (solvent). The materials are heated and stirred undervacuum (480 mm Hg) to 90° C. whereupon the vacuum is increased to 50 mmHg for 0.25 hour. The vacuum is then returned to 480 mm Hg and thetemperature is increased to 130° C. Additional ethylene glycol (30 g,0.48 mole, 0.92 eq) is added dropwise over 0.2 hour then CO₂ is thenadded via a dip tube under a slight negative pressure at 1.0 g/minute orless until 68 g (1.53 mole, 2.6 eq) are added. Upon completion of CO₂addition, the dip tube is removed and the temperature is increased to200° C. under 50 mm Hg vacuum to remove solvents. The residue is vacuumfiltered through a 12 mm diatomaceous earth pad in a sintered funnelyielding 489 g filtrate, a viscous brown liquid.

EXAMPLES 8-10 indicated below were prepared following the procedure ofExample 7:

Example 8—calcium overbased salt of Example 2 containing 10.6% Ca,

Example 9—calcium overbased salt of Example 3 containing 8.2% Ca, and

Example 10—calcium overbased salt of Example 4 containing 8.8% Ca.

EXAMPLE 11

The procedure of Example 7 is repeated except the first heat uptemperature is 95° C. and employing 100.0 g (0.04 mole, 1 eq) of theproduct of Example 5, 21 g (0.07 mole, 1.69 eq) stearic acid, 13.3 g(0.21 mole, 5.07 eq) ethylene glycol in the first charge, 23 g (0.37mole, 8.93 eq) ethylene glycol in the second charge, 28.1 g (038 mole,9.50 eq) Ca(OH)₂, 14.2 g mineral oil (SN150), 81 g 2-ethylhexanolsolvent and 27 g (0.61 mole, 15.25 eq) CO₂ to yield 165 g filtratecontaining 8.83% Ca and having TBN=240.2 and 100° C. viscosity=1435 cSt.

EXAMPLE 12

A 2 liter flask is charged with 276 g (0.348 mole, 1 eq) of the productof Example 4 which had been previously stripped to remove toluene, 2.8 g(0.045 mole, 0.13 eq) ethylene glycol, 16.9 g (0.229 mole, 0.66 eq)Ca(OH)₂, 276 g mineral oil (SN150) and 45 g 2-ethylhexanol solvent. Thematerials are heated, with stirring, to 90° C. at 63 kPa. Once at 90° C.the pressure is lowered to 17 kPa and is maintained for 0.5 hour. Thepressure is then returned to 63 kPa and the temperature is increased to130° C. where it is held for 0.3 hours. The temperature is increased to200° C. and full vacuum is applied for 0.75 hour, the vacuum is thenreleased, the residue is allowed to cool to 100° C. then is filtered.The filtrate is 560 g, 98.4% yield. % Ca=1.3, TBN=39.2 and 100° C.viscosity=99.6 cSt.

EXAMPLES 13-14as indicated below were prepared following the procedureof Example 7:

Example 13—calcium overbased salt of Example 5 having TBN of 141, and

Example 14—borated calcium overbased salt of Example 5 having TBN of 152and 0.4% B.

EXAMPLE 15

A reactor is charged with 12,960 g (8.95 moles) of the product ofExample 6, 2333 g (31.5 moles) Ca(OH)₂ and 450 g ethylene glycol. Whilestirring, 7380 g 2-ethylhexanol are added over 0.3 hour. The materialsare heated to 95° C. with −0.2 bar vacuum (˜80 kPa pressure) over 0.5hour followed by 0.8 hour at −0.56 bar vacuum (˜44 kPa pressure). After0.75 hour, 0.2 L aqueous distillate is collected. The vacuum is returnedto −0.2 bar, the materials are heated to 130° C. over 0.25 hour; totalaqueous distillate =0.5 L. An additional 2160 g ethylene glycol areadded over 0.25 hour as the temperature drops to 125° C. The temperatureis returned to 130° C. over 0.1 hour whereupon carbonation is begun at arate of 0.5 kg/hour until a total of 750 g CO₂ are added. Part waythrough the carbonation, a sample shows the presence of water; whereuponthe vacuum is reduced to −0.1 bar (˜90 kPa pressure). The temperature isincreased to 200° C. over 0.7 hour while vacuum is slowly applied to−0.56 bar. A total of about 5 L aqueous distillate are collected. Thereaction is cooled to 80° C. and collected. Yield=22.6 kg, 97% yield. %Ca=5.1; TBN=151 mg KOHIg. SO₄ ash=18%.

EXAMPLE 16

The apparatus used in Example 1 is used, except the 2 litre flask isreplaced with a 5 litre flask. The flask is charged with 1415 gpolyisobutenyl ( M _(n) 550, derived from GLISSOPAL® 550 (BASF))substituted phenol (2.2 moles, 1 eq), 576 g dodecylphenol (propylenetetramer derived, 2.2 moles, 1 equivalent (eq)); and 904 g mineral oil(SN150) and heated to 30° C. Via a pressure equalizing dropping funnel,9.9 g of 50% aqueous KOH (0.09 mole, 0.04 eq) are added all at once. Thematerials are heated to 75° C. followed by addition over 0.5 hour via apressure equalizing dropping funnel, 243.6 g 37% aqueous formaldehyde(formalin) (3.0 moles, 1.36 eq) followed by heating at 75° C. for 2hours until free formaldehyde measures less than 2% (by titration). Tothe reaction are charged 304 g salicylic acid (2.20 mole, 1.0 eq) andthe reaction is heated to 140° C. as quickly as possible (0.3 hour)while controlling reflux, draining water of reaction via a Dean Starktrap. The reaction is held at 140° C. for 1.5 hours while collecting 267ml water. The materials are vacuum stripped at 140° C./100 mm Hg over0.5 hour. The clear and golden residue is the product. Yield=3165 g, %K=0.087%. Mass spec, GPC and H¹ and C¹³ NMR indicate that the productconsists of 2 methylene bridged substituted phenol molecules methylenebridged to one salicylic acid.

EXAMPLES 17-19 as indicated below were prepared following the procedureof Example 16:

Example 17—1 equiv polyisobutyl (550 molecular wt) phenol, 1 equiv C₁₂phenol and 0.7 equiv of salicylic acid are coupled,

Example 18—1 equiv polyisobutyl (550 molecular wt) phenol, 2.5 equiv C₁₂phenol and 1 equiv salicylic acid are coupled, and

Example 19—1 equiv polyisobutyl (550 molecular wt) phenol, 7.5 equiv C₁₂phenol and 2.1 equiv salicylic acid are coupled.

EXAMPLE 20

A 2-liter flask is charged with 1200 g (1.06 moles, 1 eq) of Example 17.25 g (0.4 mole, 0.38 eq) ethylene glycol, 130 g (1.75 mole, 1.65 eq)Ca(OH)₂, and 410 g 2-ethylhexanol (solvent). The materials are heatedand stirred under vacuum (480 mm Hg) to 90° C. whereupon the vacuum isincreased to 50 mm Hg for 0.25 hour. The vacuum is then returned to 480mm Hg and the temperature is increased to 130° C. Additional ethyleneglycol (120 g, 1.93 mole, 1.82 eq) is added dropwise over 0.2 hour thenCO₂ is then added via a dip tube under a slight negative pressure at 1.0g/minute or less until 48 g (1.2 mole, 1.13 eq) are added. Uponcompletion of CO₂ addition, the dip tube is removed and the temperatureis increased to 200° C. under 50 mm Hg vacuum to remove solvents. Theresidue is vacuum filtered through a 12 mm diatomaceous earth pad in asintered funnel yielding 1346 g filtrate, a viscous brown liquid.

% Ca=5.24; TBN=156 mg KOH/g; SO₄ ash=17.3%.

EXAMPLES 21-23 indicated below were prepared following the procedure ofExample 20:

Example 21—calcium overbased metal salt of Example 18 having TBN of 145,

Example 22—calcium overbased metal salt of Example 19 having TBN of 151,and

Example 23—calcium overbased metal salt of Example 16 having TBN of 183.

Asphaltene Dispersancy

The following test assesses the level of asphaltene dispersancy providedby various phenol-salicylic acid compositions. This test relates to theproblem arising from contamination of a lubricating oil with heavy fueloil which contains residual oil to include asphaltenes.

A blend of 14.5 parts by weight of heavy fuel oil containing 10% byweight asphaltene is blended with 85.5 parts by weight Esso 150SN baseoil. Each test sample is prepared by mixing, at 60° C., 8 g of thismixture with 2 g of the component to be tested, to prepare a homogenizedmixture.

Whatman® brand extra thick chromatography paper (grade ET31) areprepared by marking each strip at 7.6 mm (immersion line), 13 mm abovethis line (spotting line) and at 15.2 cm above the spotting line(stopping line). A sample (15 μl) of each homogenized mixture is placedvia micro pipette on test strips, each test strip is suspended in a 25.4cm×2.5 cm test tube containing pentane such that the test strip isimmersed in pentane up to the immersion line. The test tubes are sealed,the 15 μl spot is allowed to elute until it reached the stopping line,then the strips are removed from the tubes and allowed to dry at roomtemperature before rating.

Each test sample is compared with a base line, a commercially availableoverbased calcium salicylate anti-black paint detergent. The ability ofthe sample to disperse asphaltene is shown by a brown streak on thechromatogram; the better the asphaltene dispersancy (and by inferenceanti-black paint activity), the higher the streak length and the lowerthe spot intensity of the spot on the spotting line.

In the two tables below the chromatogram results show embodiments of thepresent invention, Examples 8-11 and 20-23, to be about comparable orsuperior to a commercial calcium overbased salicylate base line SAP0001available from Infineum.

Streak Example number Product description length Spot intensity  7 2:1 19 dodecylphenol:salicylic acid @ 300TBN  8 1:1 2.5 6Octadecylphenol:salicylic acid @ 300TBN  9 2:1 2 2Octadecylphenol:salicylic acid @ 240TBN 10 1:1 550 PIB 6 2phenol:salicylic acid @ 250TBN 11 2:1 550 PIB 5 2 phenol:salicylic acid@ 240TBN Base line, SAP001 Commercial 5 2 salicylate 20 Overbasedproduct 8 1 of Example 17 21 Overbased product 7.0 1 of Example 18 22Overbased product 8 1 of example 19 23 Overbased product 10 1 of Example16 Base line, SAP001 Commercial 5 2 salicylatePanel Coker Test

The panel coker test is a standard industry bench oxidation test. Aweighed aluminum plate is fixed into the side of a bath and is heated to325° C. Test oil in the bath is periodically splashed onto the panelthen it is allowed to bake between splash periods. After test, the plateis removed from the bath, washed with naphtha and is then weighed,comparing the after test weight to the starting weight. The differenceis the deposit weight; the lower the deposit weight, the better theantioxidancy of the oil.

Three marine diesel lubricating oil compositions are evaluated using thepanel coker test.

Lubricant 1 is a fully formulated lubricant containing ashlesssuccinimide dispersant, mixed zinc dithiophosphate and 12.3% by weightof the product of Example 11.

Lubricant 2 is identical to lubricant 1 except the product of Example 11is replaced with an equivalent amount of a commercially available, 280TBN Ca salicylate.

Lubricant 3 is a commercially available Marine Diesel lubricantcontaining a salicylate detergent.

Test results are as follows:

Lubricant Deposit weight (mg) 1 79 2 251.5 3 139.1

The antioxidancy of the lubricant containing a product of this inventionis clearly superior to an otherwise identical lubricant containing acommercially available detergent and a commercially available marinediesel lubricant.

Engine Oil Oxidation Test

The engine oil oxidation test is a bench test that rates the oxidationresistance of crankcase engine oils. The test oil is placed in a flatbottomed test tube equipped with a water condenser and centrallyinserted gas delivery tube. The oil sample is maintained at 170° C. withair blowing. Samples are taken at 7, 10, 12 and 14 days (end of test).

The total acid number (TAN) is measured at each sampling. TAN measuresthe acidity of the oil. The greater the TAN increase, the more acidicdecomposition products are being produced and the more the oil is beingoxidized. The slower the increase in TAN, the greater the oxidationresistance of the composition.

Each of the test samples is fully formulated partial synthetic 10W-30lubricant containing an ashless dispersant, zinc dithiophosphate andother additives conventionally used in crankcase oils.

Test Sample Treatment Level Commercial 185 TBN Ca Salicylate 6 3.21Commercial 65 TBN Ca Salicylate 5.5 Commercial 285 TBN Ca Salicylate3.07 Commercial 250 TBN Sulfurized 3.26 1.75 Ca Phenate Commercial 150TBN Sulfurized 2.76 5.73 Ca Phenate Example 11 (240 TBN) 2.1 5.26Example 9 (239 TBN) 3.47 3 2.64 TAN increase @ 7 days 6.32 3.85 3.88 6.54.36 3.91 9.09 3.76 3.23 TAN increase @ 10 days 8.95 * 5.94 9.26 5.795.72 12.5 5.49 4.85 Tan increase @ 12 days 10.22 7.05 7.49 10.5 6.356.63 13.99 6.65 6.32 TAN increase @ 14 days (End of 11.49 7.05 8.1911.77 8.85 9.38 14.11 7.21 6.79 Test *Result invalidIt can be seen from the data above that Examples 9 and 11 slow the TANincrease considerably (i.e. are good antioxidants) in comparison tophenates and compare well against salicylates, especially when comparedon an equal substrate level basis.High Frequency Reciprocating Rig (HFRR)

The HFRR test is a standard industry test for wear. The test employsapparatus as described in ASTM D-6079.

Testing is conducted with blends containing 5% by weight of thespecified component in SN150 mineral oil base. The result is given in 2forms, first as a wear scar diameter in microns and then this figurestandardized to take into account atmospheric pressure, humidity andtemperature (the WS14 result). The lower the wear scar diameter and WS14figure the better. <400μ is considered a pass. Test results are

Product of Example 13: WS 14 258 μm, scar average 268 μm.

Product of Example 14: WS 14 225 μm, scar average 208 μm

Both compounds pass the test. However, the boron-containing productprovides superior antiwear performance.

TDI and T4 Engine Tests

These are severe passenger car motor oil (PCMO) engine tests which mustbe passed to meet European top tier engine oil specifications. In thesetests a matrix of 6 packages were run, 3 at 1.0% ash, 3 at 1.4% ash. The3 packages of the same ash had the TBN provided either by a standardphenate/sulphonate mix, the 150TBN overbased salt of Example 15 or165TBN salicylate ex Infineum. The packages were otherwise typical toptier European PCMO 5W-30 packages and contained identical amounts andtypes of PIB succinimide dispersants, zinc dialkyl thiophosphateantiwear agents, antioxidants and viscosity modifiers.

First the TDI results. These were run as a “no harm” test, and it can beseen that within the bounce of the test all the packages are similar,showing the Example 15 type material is not harmful to the engine and iscomparable in performance to standard salicylates or phenate/sulphonate.

The TDI results are represented in tabular form. Phenate/ Phenate/ TDISulph Salicylate Example 15 Sulph Salicylate Example 15 Criteria 1% Ash1% Ash 1% Ash 1.4% Ash 1.4% Ash 1.4% Ash Merit 59 61 59 68 68 66 (66min) Ring Stick 0.13 0 0.44 0 0 0 (0.7 max)

The T4 data is also represented in tabular form below. Phenate/ Phenate/T4 Sulph 1% Salicylate Example 15 Sulph 1.4% Salicylate Example 15Criteria Ash 1% Ash 1% Ash Ash 1.4% Ash 1.4% Ash Merit 2.22 1.69 2.943.62 4.52 5.14 (1 min) % Vis 116.1 211.2 170.7 201.9 107.7 148.0increase (130 max) EOT vis, 139.5 199.3 182.5 201.6 139.9 173.7 CSt (200max)At high ash the package containing Example 15 is overall better thanphenate/sulphonate and at low ash is overall better than salicylate. Atall ash levels Example 15 has better merit than eitherphenate/sulphonate or salicylate.OM441LA Test

This is a severe heavy duty diesel test in Europe, which is verydifficult to pass with conventional materials.

Invention Package Poor Good E4 Package 2 reference* reference limitsPiston Merit 41.5 43.3 25.9 46.6 40 Bore Polish % 0.5 1.9 0.23 1.06 2Oil consumption kg 25.3 36.6 25.2 32.5 40 *Average of 2 runsThe above table shows some recent OM441LA test runs. Package 2 is acommercial multigrade high performance ACEA E4 (the latest EuropeanTop-Tier HD specification) passing formulation. In the Invention Package(referred to in the above table) 45% of the overbased detergentsubstrate in package 2 is replaced with the 150TBN product of Example15. All the other package ingredients (PIB succinimide dispersants, zincdialkyl thiophosphate antiwear agents, antioxidants and viscositymodifiers) remain the same for both packages. It can be seen thatsubstitution of Example 15 gave similar piston merit and significantlylowered oil consumption and bore polish. The results of two standardreference oils (a “good” and a “bad”) are also given for comparison.Engine Oil Bench Tests

A standard Top Tier Heavy Duty Diesel package (“sulf/phen” in tablebelow) was run in a series of bench tests. It was then compared againstthe same package where all the overbased detergents (phenates andsulphonates) were replaced with: the 15OTBN 550 Mn PIB phenol detergentof Example 15 (“550 PIB” in the table below); the boronated 550 Mn PIBphenol detergent of Example 14 (“Borated 550 Pib” in the table below):and the dodecyl phenol detergent of Example 7 (“C₁₂” in the tablebelow). All the other package ingredients (PIB succinimide dispersants,zinc dialkyl thiophosphate antiwear agents, antioxidants and viscositymodifiers) remained the same for all the packages.

550 Borated Sulf/Phen PIB 550 PIB C₁₂ PDSC 56.6 57.8 58.4 50.6 VW sealstensile 52.2 47.1 44 54.8 VW elong 37.7 39.6 44.7 46.6 Severe VW tensile8.2 7.2 9.3 6.9 Severe VW 192 179.3 204.5 170.1 elongationOxid/nitration C═O −31.23 −16.65 −11.92 29.02 Increase Oxid/nitration 1715.1 18.3 22.3 RONO2 GF-2 TEOST 54.8 39.3 38.1 46.9

The first test (PDSC) is the Pressure Differential Scanning Calorimetertest, a standard bench test in the lubricating oil industry (CEC L-85T-99). In this test, the oil is heated to an elevated temperature andthe time to when the oil begins to decompose measured. The longer thistime, the better. It can be seen that the 550 Mn PIB-based detergent ofExample 15 (“550 PIB” in table above) and the borated detergent ofExample 14 are slightly better than the sulf/phen base line, but thedodecyl detergent of Example 7 is much worse. This is another example toshow that the alkyl chain length in the inventive detergents ispreferably C₁₈ or greater.

The next four rows concern a seal swell test using Volkswagen engineseals. In the standard test in rows 2 and 3 the lower the number thebetter. In this standard test it can be seen that C₁₂ detergent ofExample 7 performs worse than the 550 PIB detergent of Example 15 or itsborated derivative of Example 14. In the severe test in rows 4 and 5,the higher the number the better. Here the C₁₂ detergent of Example 7 isagain the worst performer, the 550 PIB detergent of Example 15 shows noharm w.r.t the standard package, but its boronated derivative of Example14 is better than the standard. This is another example to show that thealkyl chain length in inventive compounds is preferably C₁₈ or greater,and an example to show the benefit of boronation.

Rows 6 and 7 are an oxidation test where the sample is purged with NOxfor 22 hours at 145° C. and the C═O region and R—O—NO2 region monitoredbefore and after the test by FTIR. An increase in these regions is bad.In this standard test it can be seen that the C₁₂ detergent of Example 7performs worse than the than 550 Mn PIB detergent of Example 15 and itsboronated derivative of Example 14. This is another example to show thatthe alkyl chain length in the inventive compounds is preferably C₁₈ orgreater.

Row 8 is the TEOST test. In this a steel rod is cycled in the samplefrom 200-480° C. and the amount of deposits formed on the rod and in theoil are measured. The lower the deposits the better. In this test allthe examples perform better than the standard, but the C₁₂ detergent ofExample 7 performs least well of the inventive examples. This is anotherexample to show that the alkyl chain length in the inventive compoundsis preferably C₁₈ or greater.

It is known that some of the materials described above may interact inthe final formulation, so that the components of the final formulationmay be different from those that are initially added. For instance,metal ions (of, e.g., a detergent) can migrate to other acidic sites ofother molecules. The products formed thereby, including the productsformed upon employing the composition of the present invention in itsintended use, may not be susceptible of easy description. Nevertheless,all such modifications and reaction products are included within thescope of the present invention; the present invention encompasses thecomposition prepared by admixing the components described above.

Each of the documents referred to above is incorporated herein byreference. Except in the examples, or where otherwise explicitlyindicated, all numerical quantities in this description specifyingamounts of materials, reaction conditions, molecular weights, number ofcarbon atoms, and the like, are to be understood as modified by the word“about.” Unless otherwise indicated, each chemical or compositionreferred to herein should be interpreted as being a commercial gradematerial which may contain isomers, by-products, derivatives, and othersuch materials which are normally understood to be present in thecommercial grade. However, the amount of each chemical component ispresented exclusive of any solvent or diluent oil which may becustomarily present in the commercial material, unless otherwiseindicated. It is to be understood that the upper and lower amount,range, and ratio limits set forth herein may be independently combined.As used herein, the expression “consisting essentially of” permits theinclusion of substances which do not materially affect the basic andnovel characteristics of the composition under consideration.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications that fallwithin the scope of the appended claims.

1. A linear compound comprising m units of formula (I)

and n units of the formula (II)

joined together, each end of the compound having a terminal unit whichis independently hydrogen or one of the following formulae:

wherein at least one of the terminal units is formula (III) or (IV); Yis a divalent bridging group which may be the same or different in eachunit and that joins together the units of formulae (I)-(IV) and is(CHR⁶)_(d) in which R⁶ is hydrogen and d is an integer which is at least1; R⁰ is hydrogen; R⁵ is hydrogen or a hydrocarbyl group; j is 1 or 2;R³ is a hydrocarbyl or a hetero-substituted hydrocarbyl group, where R³contains 1 to 100 carbon atoms; R¹ is hydroxyl and R² and R⁴ areindependently either hydrogen, hydrocarbyl or hetero-substitutedhydrocarbyl, provided that at least one of R¹, R², R³ and R⁴ ishydrocarbyl containing on average at least 18 carbon atoms; wherein m isat least 1 and n is at least 2,; wherein on average the compoundcontains at least one unit of formula (I) or (III) and at least one unitof formula (II) or (IV); and the compound has a ratio of total number ofunits of formulae (I) and (III) to total number of units of formulae(II) and (IV) of about 0.1:1 to about 2:1; and the compound is either analkali or an alkaline earth metal salt having a TBN of 60 to 500 mgKOH/g.
 2. The linear compound of claim 1 containing at least one blockcontaining at least two units corresponding to formula (II) attached toeach other.
 3. The compound of claim 1 wherein m+n is about 3 to about50.
 4. The compound of claim 1 wherein R⁰ is hydrogen; R¹ is hydroxyl;R² and R⁴ are hydrogen; R³ is a hydrocarbyl group, R⁵ and R⁶ arehydrogen, and d is
 1. 5. The composition of claim 1 wherein the compoundcontains one or more units of formulae (II) and (IV) wherein a portionof said units have a R³ hydrocarbyl group containing about 8 to about 20carbon atoms and the remaining portion of said units have a R³hydrocarbyl group containing about 21 to about 45 carbon atoms.
 6. Thecomposition of claim 1 wherein the metal salt of the compound containsboron.
 7. A concentrate comprising the compound of claim 1 and anorganic diluent, the concentration of the organic diluent ranging fromabout 1 to about 99% by weight.
 8. A lubricating oil composition,comprising a minor amount of the compound of claim 1 and a major amountof a lubricating oil.
 9. The lubricating oil composition of claim 8wherein the lubricating oil composition further comprises a contaminateamount of fuel oil having a residual oil content.
 10. A process formaking a linear compound metal salt comprising the steps: step (I)preparing the linear compound by reacting together, optionally in anorganic solvent, and in the presence of a basic catalyst, compounds ofthe formulas (Ia) and (IIa)

with an aldehyde; wherein R⁰ is hydrogen or a hydrocarbyl group; R⁵ ishydrogen or a hydrocarbyl group; j is 1 or 2; R³ is a hydrocarbyl or ahetero-substituted hydrocarbyl group, where R³ contains 1 to 100 carbonatoms; R¹ is hydroxyl and R² and R⁴ are independently either hydrogen,hydrocarbyl or hetero-substituted hydrocarbyl, provided that at leastone of R¹, R², R³ and R⁴ is hydrocarbyl containing on average at least18 carbon atoms; the number of molar units of the compound representedby formula (Ia) being m, the number of molar units of the compoundrepresented by formula (IIa) being n, wherein m is at least 1 and n isat least 2, and the ratio ofm ton ranging from about 0.1:1 to about 2:1;step (II) forming a mixture of components (A) and (C); component (A)being the compound prepared in step (I); component (C) being a solventcomprising either component (C-1) or (C-2); component (C-1) being either(i) a polyhydric alcohol having 2 to 4 carbon atoms; (ii) a di-(C₃ orC₄) glycol, (iii) a tri-(C₂-C₄) glycol or (iv) a mono- or poly-alkyleneglycol alkyl ether of the formula:R¹(OR²)_(f)OR³  (V) wherein the formula (V), R¹is an alkyl group of 1 toabout 6 carbon atoms, R² is an alkylene group of 1 to about 6 carbonatoms, R³ is hydrogen or an alkyl group of 1 to about 8 carbon atoms,and f is an integer from 1 to about 6; component (C-2) being amonohydric alcohol of 1 to about 4 carbon atoms in combination with ahydrocarbon solvent; and step (III) adding ametal base (B)to the mixtureof components (A) and (C), the addition of the metal base (B) to themixture of (A) and (C) being in a single addition or in a plurality ofadditions, steps (II) and (III) being performed concurrently orsequentially.
 11. The process of claim 10 including an initialoli-gomerization step in step (I) wherein the compound corresponding toformula (IIa) is permitted to react prior to the addition of thecompound corresponding to formula (Ia).
 12. The process of claim 10wherein to basic catalyst is alkali or alkaline earth metal hydroxide,ammonia, a hindered amine or a basic ion exchange resin.
 13. The processof claim 10 with the additional step of: Step (IV) adding (D) carbondioxide to the mixture of components (A), (B) and (C) subsequent to eachaddition of component (B).
 14. The process of claim 13 wherein duringstep (I), (II), (III) or (IV), or prior to or subsequent to step (I),(II), (III) or (IV), the reaction mixture further comprises component(E); component (B) being either (i) a carboxylic acid or anhydridethereof containing about 6 to about 100 carbon atoms; (ii) a di- orpolycarboxylic acid or anhydride thereof containing from about 36 toabout 100 carbon atoms; (iii) a hydrocarbyl-substituted sulphonic acidor anhydride thereof; (iv) a hydrocarbyl-substituted salicylic acid oranhydride thereof; (v) a hydrocarbyl-substituted naphthenic acid oranhydride thereof; (vi) a hydrocarbyl-substituted phenol; or (vii) amixture of two or more of (i) to (vi).
 15. The process of claim 10wherein the mole equivalent ratio of component (B) to component (A) isfrom about 0.05 to about 20 mole equivalents of(B) per mole equivalentof(A).